I assume that 1) the "number of processors" means either number of cores or physical processors, and 2) if the "number of processors" is not check marked, then all cores or physical processors are made available. Am I correct?

short story: I was having performance issues in BC2 back when it was new, noticed in cpu monitor that I was only showing two cores, didn't think much of it. Couple weeks later I stumble upon a thread talking about this command. Mine was unchecked (which is supposed to cause windows to use all cores). I checked it, rebooted. Unchecked it again, rebooted. Checked my cpu monitor again and BOOM four cores showing.

If you're having issues with core(s) not showing up, might wanna try this.

churin wrote:Sometimes only one of the four cores of my cpu is shown on the task manager. I had to do as lilbudhamman's post. I wonder if there is a way to prevent it from happening.

You're sure that's not just the way Taskman happens to be displaying things (View menu, CPU History)? Also, you can use perfmon or Resource Monitor to double-check. (I hardly ever use TaskMan anymore as Process Explorer and Resource Monitor are more generally useful)